System and method for providing tempered fluid

ABSTRACT

The present invention is directed to methods and apparatus for tempering the temperature of a liquid in a fluid conducting system. More particularly, some embodiments of the invention relates to tempering the temperature of water supplied to a fixture from a water heater in a fluid conducting system. The system can include a heater for heating the fluid and a diffuser for slowing the rate at which water provided to a decontamination fixture is heated.

This application claims priority to U.S. patent application Ser. No. 11/180,380, filed Jul. 13, 2005, which claims priority to U.S. Provisional Application No. 60/592,710, filed Jul. 30, 2004, herein incorporated by reference in its entirety.

BACKGROUND AND SUMMARY OF THE INVENTION

The present invention concerns a method and apparatus for tempering the temperature of a liquid in a fluid conducting system. More particularly, the invention relates to tempering the temperature of water supplied to a fixture from a water heater in a fluid conducting system.

Thermally controlled or thermostatic mixing valves are well known. Valves of this type receive both hot and cold fluid, typically water, and allow the fluids to mix to an intermediate temperature. The temperature is controlled using a thermally responsive control member, such as a thermostat, to assist in maintaining the fluid temperature according to an established setting.

One particular application of thermostatic mixing valves is in connection with emergency shower and eyewash systems. Toxic and hazardous chemicals are used in many environments, whether inside a factory building or outside at a remote construction site. The Occupational Safety and Health Act of 1970 was enacted to assure that workers would be provided with safe and healthful working conditions. Pursuant to this act, the Occupational Safety and Health Administration adopted regulations which require the availability of emergency eyewash and shower equipment for use as a form of first aid treatment. Emergency shower and eyewash systems have proliferated in a wide range of industries, including automotive, food processing, chemical processing, petroleum refining, steel production, pulp and paper, and waste water treatment. In each of these industries, workers may be exposed to chemicals that may cause serious tissue damage and destruction. These emergency shower and eyewash facilities are commonly associated with permanent structures and may be located inside or outside factory buildings with access to hot and cold water.

In emergency fixture systems such as eyewash and emergency shower systems, even ground water of a moderate temperature (such as in the range of 50 degrees to 60 degrees F., as is common) is often perceived to be too cold, possibly discouraging sufficient duration of use of the emergency equipment. In addition, in northern climates, the ground water itself is sometimes barely above freezing, commonly near 35 degrees F. Under these circumstances, an emergency shower and eyewash system relying solely upon ground water often provides water that would be too cold to be endured for a sufficient period of time, even by a victim of a chemical accident.

As a result, emergency shower and eyewash systems have been designed to provide tempered water by blending relatively hotter water with relatively colder water. A range of temperatures between 65 degrees F. to 95 degrees F. is comfortable to most persons. To provide tempered water within this range, most emergency fixture systems include a source of hot water, typically in the range of 140 degrees F. to 160 degrees F., that is mixed with ambient ground water.

Many outdoor or other remote worksites such as construction sites may have the same or similar hazards that are associated with indoor worksites. Such remote worksites typically do not have a ready supply of hot water. Thus, workers at such sites exposed to chemicals or other irritants typically do not have access to emergency fixture systems that provide an adequate supply of tempered fluid, properly directed, for a sufficient period of time. Such workers may be required to resort to a ground-temperature water supply from a garden hose, a squirt bottle eye rinse apparatus, or other less suitable sources of fluid to rinse the exposed area(s).

Emergency shower and eyewash systems must typically drench or rinse a user for at least 15 minutes. Thus, the source of tempered water should be able to provide the water for at least that length of time and to maintain the water within a comfortable temperature range for the user. In addition, the system should be able to maintain tempering of the water regardless of extreme fluctuations in the supply of hot or cold water to the thermostatic mixing valve. Often, a thermostatic mixing valve is used to maintain the water at an appropriately tempered temperature.

The valve should respond accordingly to failures in the supply of hot or cold water to the valve, as well as failure of the valve itself. The valve should respond to these failures without placing the user of the emergency shower or eyewash system in greater peril than the user would be without the emergency system. For example, if the cold water supply fails and only hot water in the range of 140 degrees F. to 160 degrees F. is supplied, the user could suffer burns that may be more serious than the exposure being treated. Thus, it is desirable for the valve to prevent or minimize exposure to such hot water.

Thermostatic mixing valves typically include a housing including hot and cold inlets, a mixed fluid outlet, a valve control assembly to adjust the amounts of hot and/or cold fluid permitted to flow through the valve, and a thermostat to control movement of the control assembly. The thermostat is typically positioned at least partially in the housing to sense the temperature of the mixture of fluid therein. The thermostat includes a material that is responsive to changes in the fluid temperature. For example, if the temperature increases, then movement of the thermostat causes movement of the control assembly, either increasing the flow of cold fluid, decreasing the flow of hot fluid, or both.

Frequently, some fluid in the fluid circulation system of which the thermostatic mixing valve is a part has been stagnant for a period of time. During this stagnancy, the temperature of the hot fluid in the hot fluid supply line approaches ambient temperature, usually lower than the temperature of the hot fluid from the hot fluid supply. In a typical thermostatic mixing valve, when the temperature of the mixed fluid sensed by the thermostat is below the set point, the thermostat cooperates with the valve control assembly to increase the flow of hot fluid relative to the flow of cold fluid.

In such a stagnant fluid circulation system, when a fixture (such as an eyewash station) is eventually actuated, the thermostat is often exposed to mixed water at a temperature below the set point temperature, even if the ratio of water from the hot and cold fluid supplies otherwise would be proportioned (if the hot fluid were at temperature) to produce mixed fluid at the desired temperature. Accordingly, responsive changes in the thermostat cause the valve control assembly to move to a position that increases the flow of hot fluid relative to the flow of cold fluid, thus increasing the mixed fluid temperature. As the valve continues to receive the supply of fluid from the hot fluid supply line that was formerly stagnant, the thermostat continues to cause the valve control assembly to move to a position that further increases flow from the hot fluid supply line and/or decreases the flow of cold fluid. If a sufficient volume of stagnant fluid is in the supply line between the hot fluid supply and the mixing valve, this process may continue until the thermostat has caused the valve assembly to move to a position wide-open to maximize the flow of fluid from the hot fluid source.

Eventually, hot fluid from in the hot fluid supply (such as a water heater) progresses to the mixing valve. Because the valve control assembly is now wide-open to the hot fluid inlet, a large volume of hot fluid enters the valve housing through the hot fluid supply line that had previously been the source of the stagnant (and cooler) fluid. Once the hot fluid reaches the thermostat after mixing with whatever cold fluid is entering the valve, the thermostat responds to the temperature increase, causing the valve control assembly to move to reduce the flow of hot fluid and/or increase the flow of cold fluid. The length of time for the thermostat to respond as such and move the valve control assembly by a sufficient amount to reduce the temperature of mixed fluid below the set point can be long enough to permit a quantity of water above the set point temperature to flow from the valve.

Thus, in one aspect of the invention, a decontamination apparatus is provided, comprising a fluid supply inlet configured for coupling to a fluid supply source, a first fluid line coupled to the fluid supply inlet and formed to include a first passageway in which a first fluid flows, and a heat exchange assembly configured to heat the first fluid in the first fluid line. The apparatus also comprises a mixing valve including a valve body formed to include a first fluid inlet to receive the first fluid from the first fluid line, a second fluid inlet to receive a second fluid from a second fluid line, and a mixed fluid outlet. A decontamination fixture is coupled to the mixed fluid outlet configured to discharge the mixed fluid. Optionally, a support interconnects at least the heat exchange assembly, the first fluid line, the mixing valve, and the decontamination fixture to permit movement of the apparatus as a unit.

In one illustrative example according to this aspect of the invention, the support is a frame including frame members coupled together, a platform coupled to the frame, and wheels coupled to the frame to facilitate movement of the decontamination apparatus.

In another illustrative example according to this aspect of the invention, the support includes a platform having a structure including a generally upwardly facing surface on which the heat exchange assembly, mixing valve, and decontamination fixture are supported, and a plurality of spaced apart support members coupled to and extending downwardly from the structure.

Illustratively according to this aspect of the invention, the first and second fluid lines comprise fluid provided by the fluid supply source.

Additionally illustratively according to this aspect of the invention the apparatus further comprises a junction in fluid communication with the fluid supply inlet, the junction splitting flow of fluid from the fluid supply source into the first fluid line and the second fluid line.

Illustratively according to this aspect of the invention the second fluid line configured to be coupled to a second fluid supply source and formed to include a second passageway in which a second fluid stream flows.

Illustratively according to this aspect of the invention the heat exchange assembly comprises a burner configured to combust fuel from a fuel source, and at least a portion of the first fluid passageway is proximate the burner so that when fuel from the fuel source is combusted at the burner, heat from the combustion is transferred into the first fluid in the first fluid passageway.

Additionally illustratively according to this aspect of the invention, the burner is coupled to a controller, the decontamination fixture includes an actuator to actuate a valve controlling flow of fluid from the decontamination fixture, the burner igniting upon actuation of the decontamination fixture by a signal sent by the controller.

Additionally illustratively according to this aspect of the invention the apparatus further comprises a fuel tank in which the fuel is stored, the fuel tank coupled to the frame to enable movement of the fuel tank upon movement of the frame.

Illustratively according to this aspect of the invention the apparatus further comprises wheels coupled to the frame to facilitate movement of the decontamination apparatus.

Additionally illustratively according to this aspect of the invention the apparatus further comprises a stand coupled to the frame to cooperate with the wheels to maintain decontamination apparatus in a position suitable for use by a user.

Illustratively according to this aspect of the invention, the apparatus further comprises a means for dampening temperature change of the first fluid prior to entry into the first fluid inlet of the thermostatic mixing valve so that the mixing valve can adjust to a particular temperature increase over a given time period.

Illustratively according to this aspect of the invention, the apparatus further comprises a diffuser coupled between the hot fluid line and the hot inlet to the mixing valve, the diffuser including a first fluid conduit and at least a second fluid conduit, a majority of the first fluid conduit being surrounded by the second fluid conduit, the first and second conduits being coupled together to cause fluid to flow into the first conduit, pass through a plurality of apertures formed in the first conduit, and into fluid outside the first conduit and in the second conduit.

Illustratively according to this aspect of the invention, the decontamination fixture is an eyewash fixture including a basin and at least one nozzle directed at least partially upwardly.

Illustratively according to this aspect of the invention, the decontamination fixture is a drench shower having fluid outlets directed at least partially downwardly.

Illustratively according to this aspect of the invention, the decontamination fixture is a wand including a trigger configured to be actuated by a user and a spray nozzle to direct the flow of fluid from the wand depending on a direction selected by a user.

According to another aspect of the invention, an apparatus for increasing the time period over which a temperature change occurs at a point in a fluid conducting system having fluid flowing therethrough comprises a first conduit having first and second ends and a plurality of openings provided between the first and second ends, a second conduit having first and second ends, the second conduit being coupled to the first conduit and at least partially surrounding at least a portion of the first conduit, wherein at least one of the openings is in the portion of the first conduit surrounded by the second conduit, one of the second conduit and the first conduit including a fluid inlet, and the other of the second conduit and the first conduit including a fluid outlet, wherein the first and second conduits are arranged to permit fluid to flow from the inlet to the outlet.

Illustratively according to this aspect of the invention, the second conduit and the first conduit are connected together to permit fluid to flow from the fluid inlet toward the fluid outlet.

Additionally illustratively according to this aspect of the invention, the first conduit and the second conduit are coupled together by a union that seals a first end of each of the first and second conduit so that fluid is inhibited from passing from the first end of the first conduit into the region between the first and second conduits adjacent the first end of the first conduit.

Further illustratively according to this aspect of the invention, a second end of the second conduit is sealed with a cap to prevent fluid from flowing out of the second end of the second conduit.

Further illustratively according to this aspect of the invention, a second end of the first conduit is spaced apart from the cap to permit fluid to flow from the second end of the first conduit adjacent the cap, and into the region between the first and second conduits.

Additionally illustratively according to this aspect of the invention, the union is formed to include an outlet to permit fluid to flow from the first end of the second conduit out of the outlet.

Further illustratively according to this aspect of the invention, the union includes a first end having an opening sized to receive the first end of the second conduit, and the union includes a second end having an opening sized to receive the first end of the first conduit.

Further illustratively according to this aspect of the invention, the first and second ends of the union are separated by a generally frustoconical reducing region.

Illustratively according to this aspect of the invention, the first and second fluid conduits are coupled so that fluid flowing within the first conduit flows substantially in the opposite direction as fluid flowing within the second conduit.

Additionally illustratively according to this aspect of the invention, the apparatus further comprises a third fluid conduit, wherein at least a portion of the first fluid conduit is surrounded by the second and third fluid conduits, and at least a portion of the second fluid conduit is surrounded by the third fluid conduit.

Further illustratively according to this aspect of the invention, the fluid flowing through and immediately adjacent to the first and third fluid conduits flows in a direction substantially parallel within each conduit.

Illustratively according to this aspect of the invention, the apparatus further comprises a plurality of apertures in the second fluid conduit comprise a first aperture, a second aperture, and a third aperture, the first aperture being spaced from the second aperture by a first distance, and the second aperture being spaced from the third aperture a second distance, the first distance being greater than the second.

Illustratively according to this aspect of the invention, the first and second fluid conduits define a void having a volume capable of receiving at least 0.13 gallons of fluid.

Additionally illustratively according to this aspect of the invention, the first, second and third conduits define a void having a volume capable of receiving at least 0.9 gallons of fluid.

Illustratively according to this aspect of the invention, the plurality of each of the apertures is substantially of one of the shapes selected from the group consisting of: circular, square, rectangular, diamond-shaped, ovular, triangular, and irregular.

According to another aspect of the invention, a fluid mixing apparatus for use in a fluid flow network comprises a mixing valve including a housing having a hot fluid inlet, a cold fluid inlet, a mixed fluid outlet, a mixing region, and a movable valve assembly to adjust the relative flow of fluid through the hot fluid inlet and the cold fluid inlet, and a first fluid conduit in fluid communication with the mixing valve, the first fluid conduit including an inlet through which fluid flows from a hot fluid supply line and an outlet through which fluid flows toward the mixing valve, the first fluid conduit constructed to expose fluid flowing through the inlet to a heat sink.

Illustratively according to this aspect of the invention, the heat sink is a second fluid mass downstream of a first fluid mass. Additionally illustratively according to this aspect of the invention, the apparatus further comprises a second fluid conduit coupled to the first fluid conduit, the first fluid conduit formed to include the inlet and formed to include a first conduit outlet through which fluid is capable of flowing out of the first fluid conduit and into the second fluid conduit. Further illustratively according to this aspect of the invention, the apparatus further comprises a third conduit between the first and second fluid conduits. Additionally illustratively according to this aspect of the invention, the first fluid conduit has a length, and is formed to include a plurality of openings, at least one of the plurality of openings positioned between the ends of the first fluid conduit. Additionally illustratively according to this aspect of the invention, a portion of the first fluid conduit is surrounded by the second fluid conduit. Additionally illustratively according to this aspect of the invention, at least one of the first and second fluid conduits includes a plurality of fins extending from a surface of said one of the first and second fluid conduits. Further illustratively according to this aspect of the invention, said one of the first and second fluid conduits is formed to include a plurality of apertures, at least one of said plurality of apertures positioned between the ends of the fluid conduit including fins.

Illustratively according to this aspect of the invention, the heat sink is a thermally conductive material having a mass per unit of linear length of net fluid flow greater than the average mass per unit of linear length of net fluid flow in the fluid flow network. Additionally illustratively according to this aspect of the invention, the heat sink comprises copper.

Illustratively according to this aspect of the invention, the heat sink surrounds the first conduit so that fluid flowing from the first fluid conduit subsequently flows through a passageway defined by the heat sink.

According to another aspect of the invention a decontamination apparatus comprising a fluid heater, a cold fluid supply line, a hot fluid supply line for supplying hot fluid from the fluid heater to a thermostatic mixing valve, the thermostatic mixing valve having a hot fluid inlet for receiving fluid from to the hot fluid supply line, a cold fluid inlet for receiving fluid from the cold fluid supply line, and a mixed fluid outlet for supplying fluid to a mixed fluid supply line through which one, the other, or both of the hot and cold fluids flow from the thermostatic mixing valve, an emergency fixture connected to the mixed fluid supply line for supplying fluid therefrom to a user and configured to deliver the mixed fluid at a flow rate and pattern to decontaminate effectively at least a portion of the user's body, and a diffuser coupled between the hot fluid supply line and the thermostatic mixing valve for increasing the time over which a temperature change is observed at the hot fluid inlet.

In another aspect of the invention a decontamination apparatus comprises a fluid supply inlet configured for coupling to a fluid supply source, a circulation network coupled to the fluid supply inlet and formed to include a first passageway in which a first fluid flows, a heater to heat the first fluid stream in the circulation network, a decontamination fixture connected to the circulation network to receive heated fluid from the heater, and a support interconnecting at least the heater, fluid circulation network, and the decontamination fixture to permit movement of the apparatus as a unit.

Illustratively according to this aspect of the invention, the apparatus further comprises a mixing valve comprising a valve body formed to include a first fluid inlet to receive a first fluid from a first fluid line, a second fluid inlet to receive a second fluid from a second fluid line, and a mixed fluid outlet. Additionally illustratively according to this aspect of the invention, the mixing valve further includes a valve assembly operably coupled to a thermostat to move the valve assembly to adjust the flow of at least one of the first and the second fluids to control the mixed fluid temperature.

Additionally illustratively according to this aspect of the invention, the support is a pallet into which the tines of a fork truck can be inserted to lift and move the apparatus as a unit. Additionally illustratively according to this aspect of the invention, the support is a frame having wheels coupled thereto so that a user can move the apparatus as a unit. Additionally illustratively according to this aspect of the invention, the decontamination fixture includes a valve operated by an actuator, and operation of the actuator causes fluid to flow from the circulation network through the mixing valve and through the decontamination fixture. Further illustratively according to this aspect of the invention, operation of the actuator causes the heater to ignite and heat the fluid flowing through the circulation network.

Additionally illustratively according to this aspect of the invention, the apparatus further comprises a diffuser positioned in the circulation network to receive fluid from the heater, the diffuser configured to increase the time over which a temperature increase is observed at the inlet of the fluid from the heater to the mixing valve.

Illustratively according to this aspect of the invention, the apparatus further comprises a fuel tank to store fuel usable by the heater to generate heat for heating the fluid in the circulation network. Additionally illustratively according to this aspect of the invention, the support is a frame having wheels coupled thereto so that a user can move the apparatus as a unit.

Additionally illustratively according to this aspect of the invention, the heater is configured to heat fluid on demand as the fluid flows through the circulation network.

Illustratively according to this aspect of the invention, the heater includes a storage tank and is configured to heat fluid and store the heated fluid in the storage tank.

Additional features of the invention will become apparent to those skilled in the art upon consideration of the following detailed description of a preferred embodiment exemplifying the best mode of carrying out the invention as presently perceived.

BRIEF DESCRIPTION OF DRAWINGS

The detailed description particularly refers to the accompanying figures in which:

FIG. 1 illustrates a decontamination apparatus for tempering fluid to rinse substances from body parts of a victim, the apparatus having a heat exchange unit, fuel source, decontamination fixture, fluid circulation network, diffuser, and mixing valve coupled with a support to facilitate transportation of the decontamination apparatus;

FIG. 2 illustrates internal components of an illustrative heater for use with the decontamination apparatus of FIG. 1;

FIG. 3 illustrates a decontamination apparatus for tempering fluid including a heat exchange unit, fluid circulation network, decontamination fixture, diffuser, and mixing valve positioned on a support platform to facilitate transportation of the decontamination apparatus;

FIG. 4 is a cross-sectional view of the diffuser shown in FIG. 1, taken along line 4-4 thereof, showing the first and second conduits cooperating to form a two-pass diffuser;

FIG. 5 is a cross-sectional view of the diffuser shown in FIG. 3, taken along line 5-5 thereof, showing the first, second, and third conduits cooperating to form a two-pass diffuser;

FIG. 6 is a perspective view of a decontamination fixture including a drench shower and an eyewash station;

FIG. 7 is a perspective view of a conduit for a diffuser having a spiral fin projecting away from the centerline through the conduit;

FIG. 8 is a cross-sectional view of a conduit for a diffuser having a plurality of holes formed therein;

FIG. 9 is a cross-sectional view of a conduit for a diffuser similar to FIG. 8 showing a hole having a diamond shape;

FIG. 10 is a cross-sectional view of a conduit for a diffuser similar to FIG. 8 showing a hole having an oval shape;

FIG. 11 is a cross-sectional view of a conduit for a diffuser similar to FIG. 8 showing a slot having a elongated rectangular shape;

FIG. 12 is a cross-sectional view of a conduit for a diffuser similar to FIG. 8 showing a hole having a trapezoidal shape;

FIG. 13 is a cross-sectional view of a conduit for a diffuser similar to FIG. 8 showing a plurality of circular holes spaced apart by varying distances;

FIG. 14 is a fragmentary view of a portion of the heater of FIG. 2, showing a pilot assembly with an igniter and a flame sensor;

FIG. 15 is a view of the pilot assembly of FIG. 14 showing a pilot flame;

FIG. 16 is a diagrammatic view of the heater of FIG. 2, showing a computer connected to a gas proportioning valve, to a flow sensor that is also coupled to the fluid inlet to the heater, and to a thermistor that is also coupled to the hot fluid outlet line, the heat exchanger and a fuel inlet line;

FIG. 17 is a schematic view of the heater of FIG. 2 showing safety circuitry including an overheat sensor, temperature limiter, and flue gas safety sensors and switches arranged in series and coupled to a valve to shut off flow of fuel upon detection of certain conditions;

FIG. 18 is a diagrammatic view of a decontamination apparatus including a fluid supply, a heat exchanger receiving fluid from the fluid supply and feeding heated fluid to a diffuser, the diffuser feeding fluid to a mixing valve that, optionally, receives a supply of cold fluid from a cold fluid source, and a mixed fluid stream flowing from the mixing valve to an optional second diffuser then to an application;

FIGS. 19A through 19G are graphical data, also shown in tabular form in Table 1, of a test performed with a circulation system including hot and cold inlets, a diffuser similar to the diffuser of FIG. 5, and a mixed fluid outlet coupled to the diffuser, wherein -♦- represents cold water, -▪- represents hot water, -▴- represents mixed water temperature, and -x- represents water pressure; and

FIG. 20 is a diagrammatic view of a test apparatus showing a cold fluid supply, a hot fluid supply, a mixed fluid outlet, a diffuser coupled between the supplies and the mixed fluid outlet, and decontamination apparatus including a plurality of sensors coupled to the test apparatus to provide data.

DETAILED DESCRIPTION

As illustrated in FIG. 1, a decontamination apparatus 20 includes a heat exchange assembly 22, a fluid circulation network 24, and a mixing valve 26. In the embodiment of FIG. 1, the heat exchange assembly includes a heater 28 for supplying heat to a fluid for increasing the temperature of the fluid. To facilitate transportation of decontamination apparatus 20, a support 32 is illustratively provided and is connected to fluid circulation network 24 and heat exchange assembly 22. A plurality of wheels 34 and a stand 36 are coupled to frame 32. Wheels 34 and stand 36 cooperate with support 32, illustratively a frame 33, to support fluid circulation network 24 and heat exchange assembly 22 in the position depicted in FIG. 1.

Circulation network 24 includes fluid supply inlet 40 to which a fluid supply line 42 is couplable, fluid supply line 42 illustratively shown as a hose in FIG. 1. Fluid supply inlet 40 leads to a tee or other junction 44 at which fluid flowing through circulation network 24 is divided—a portion of the fluid flows into a cold fluid line 46 and a portion flows into hot fluid line 48. Cold fluid line 46 extends from junction 44 to mixing valve 26, and is coupled to cold inlet 50 of mixing valve 26. Hot fluid line 48 extends from junction 44, to heater 28, and is coupled to mixing valve 26. As fluid flows through hot fluid line 48 adjacent heater 28, heat generated by heater 28 is applied to hot fluid line 48, increasing the temperature of the fluid flowing therein. Hot fluid line 48 is coupled to hot inlet 52 of mixing valve 26. Although FIG. 1 discloses junction 44 as dividing a single supply line into the hot and cold fluid streams, it is within the scope of this disclosure to have separate hot and cold fluid supply lines supplying respective hot and cold fluids.

As illustrated in FIG. 1, mixing valve 26 includes a housing 54 in which are mixed hot fluid flowing through hot inlet 52 and cold fluid flowing through cold inlet 50. Illustratively, mixed fluid temperature is controlled using a suitable thermostat and valve assembly, as is known in the art. While reference is made to thermostatic mixing valves, it is within the scope of this disclosure to use other types of mixing valves or systems as are known in the art, illustratively proportional mixing techniques, pressure balancing valves, and the like. Mixed fluid flows from housing 54 through mixed fluid outlet 56, and into mixed fluid line 58. Mixed fluid line 58 leads to an emergency fixture depicted illustratively in FIG. 1 as an eyewash fixture 37.

As illustrated in FIG. 1, circulation network 24 has positioned therein a first diffuser 30 between the portion of hot fluid line 48 adjacent heater 28 and hot inlet 52 of mixing valve 26. Illustratively, circulation network 24 has positioned therein a second diffuser 30A between mixed fluid outlet 56 from mixing valve 26 and eyewash fluid inlet line 38. Eyewash fluid inlet line 38 includes a valve 39 therein that is operable by actuation of actuator 41. When a user actuates actuator 41, opening valve 39, mixed fluid flows from mixed fluid outlet 56 through mixed fluid line 58, toward eyewash fixture 37, through eyewash fluid line 38, and out eyewash outlets 43 of eyewash fixture 37. Refuse fluid is captured, at least in part, by basin 45 and is permitted to exit by way of drain 47. Illustratively, when a user actuates actuator 41, a burner or other heating element (described more fully below) is ignited or otherwise powered to heat fluid flowing through hot fluid line 48. Optionally, decontamination apparatus 20 can be provided as a mobile unit.

As illustrated in FIG. 1, frame 33 includes side members 35 that are coupled to heater 28. Side members 35 are coupled to a base 49 illustratively including an axle tube 51 coupled to lower ends of side members 35 and an axle (not shown) extending therethrough. Wheels 34 are coupled to the axle to facilitate transport of decontamination apparatus 20. Base 49 of frame 33 further includes a platform 53 having a generally upwardly facing surface 55. Handles 57 are coupled to side frame members 35 to further facilitate transport. Upper frame section 59 is connected to side members 35, and illustratively is a generally rectangular tubular section that extends outwardly from side members 35 to provide additional support for heater 28. Also connected to frame 33 are circulation network 24, mixing valve 26, fuel tank 112, and emergency (eyewash) fixture 37, whether directly connected to frame 33 or indirectly through other parts of decontamination apparatus 20. To move decontamination apparatus 20, a user simply disconnects any fluid supply line 42 connected to fluid supply inlet. The user positions a foot on axle tube 51 and pulls handles 57 in direction 61, lifting stand 36 from engagement with the ground or floor. The user can then move decontamination apparatus 20 by guiding handles 57 and rolling the apparatus using wheels 34.

Other fixtures are possible and are within the scope of this disclosure. For example, a decontamination fixture having one or more sprayers or wands (not shown) may be included. Such a sprayer or wand could include a trigger or other actuator that can be actuated by a user. The sprayer or wand may include a spray nozzle to create a desired pattern of spray. A user can use such a sprayer or wand to direct the flow of fluid from the wand in a pattern and/or a direction selected by a user.

As shown in FIG. 3, decontamination apparatus 320, described in further detail below, is positioned on support 332. Support 332 is a platform 333 upon which is positioned a heater 328, emergency fixture 510, and illustratively mixing valve 326. Platform 333 includes a generally upwardly facing surface 335 sized to support heater 328 and emergency fixture 510 thereon. Support members 337 extend from platform 333 downwardly toward base 339. Support members 337 are illustratively spaced apart from each other and are positioned to receive the tines of a fork truck, or other transportation or lifting device, therein to permit convenient transport of decontamination apparatus 320. To move decontamination apparatus 320 from one location to another, any fluid supply lines, drain lines, and fuel (or other power source) lines are disconnected, and transportation or lifting device (not shown) is positioned in spaces between support members 337 and platform 333 is lifted so that support 332 and decontamination apparatus 320 are elevated above the ground or floor. Decontamination apparatus 320 is then moved to the desired location.

While decontamination apparatus 20 of FIG. 1 and decontamination apparatus 320 of FIG. 3 are illustrative examples configured for convenient transport, using frame 20 of FIG. 1 and using a fork-truck or similar device to transport apparatus 320 of FIG. 3, it is understood that other configurations are within the scope of this disclosure. Other portable, semi-portable, and non-portable configurations are contemplated. A self-contained fluid supply vessel may be provided instead of using water from a source such as a well, municipal water supply, or other similar water source. Such an apparatus could be transported using a transportation device such as a truck, automobile, military vehicle, train, helicopter, or other mode of transportation. A decontamination apparatus such as apparatus 320 of FIG. 3 could be affixed using known methods to a structure in a building, for example, if portability of the apparatus is not desired.

In one configuration rather than having a burner, heating element 314 is provided in an electric heater that enables a user to set the temperature of hot water in the hot water supply to achieve and maintain a higher temperature than is possible with typical residential water heater heating elements. In one exemplary configuration, a tubular heating element manufactured by Watlow Electric Manufacturing Company, 12001 Lackland Road, St. Louis, Mo., USA 63146 is capable of maintaining water at and above 180 degrees F. at typical flows for a sufficient time to satisfy requirements for emergency applications. Such heating elements are typically constructed to withstand higher temperatures and currents than standard residential heating elements. Further, thermostats associated with such heating elements are constructed to permit a user to select a temperature above about 185 degrees F.

Referring to FIG. 4, diffuser 30 includes a first conduit 60 and a second conduit 62 surrounding, illustratively, a majority of first conduit 60. First conduit 60 includes a first end 64 serving as an inlet of fluid to diffuser 30, and an opposite second end 66. Second conduit 62 includes a first end 74 serving as an outlet for fluid from diffuser 30 and an opposite second end 76. As illustrated in FIG. 4, a cap 68 is coupled to second end 76 to close second conduit 62. Cap 68 is coupled to second end 76 illustratively with solder applied around the perimeter of cap 68. It is understood that this diffuser design is illustrative only and that it is within the scope of this disclosure for diffusers to be different in design.

In the illustrative embodiment, diffuser 30 includes a union 70 to assist in positioning first conduit 60 relative to second conduit 62 and to assist in directing or guiding the flow of fluid through diffuser 30. Union 70 is coupled to first ends 64, 74 of respective first and second conduits 60, 62, illustratively with solder. Union 70 includes, at a first end 71 thereof, a first opening 72 to receive first end 74 of second conduit 62. Union 70 includes, at a second end 73 thereof, a second opening 78 sized to receive first end 64 of first conduit 60.

Referring to FIG. 4, in operation, fluid enters diffuser 30 through first end 64 of first conduit 60 adjacent second end 73 of union 70. Depending on the outlet configuration (described in more detail below), fluid generally flows in first direction 80 through first conduit 60 from its first end 64 to its second end 66. Second end 66 is spaced apart from cap 68, permitting fluid to exit second end 66 of first conduit 60 and reverse its direction to flow in a second direction 82, opposite first direction 80. First conduit 60 is positioned substantially within second conduit 62 so that when fluid exits second end 66, the fluid remains within the volume defined by cap 68, second conduit 62, and portions of union 70.

As shown in FIG. 4, union 70 includes, between its first and second ends 71, 73, a reducing region 75 that necks down or reduces the diameter of union 70 from a diameter sized to receive the outside diameter of second conduit 62 to a diameter sized to receive the outside diameter of first conduit 60, thus forming a seal to prevent fluid from flowing from second conduit 62 out of the fluid circulation network between first conduit 60 and second end 73 of union 70. Union 70 includes an outlet 86 formed between first end 71 thereof and reducing region 75. Illustratively, reducing region 75 is frustoconical in shape. An outlet 86 surrounds an opening 88 formed in union 70 to permit fluid flowing in direction 82 to exit diffuser 30 and flow toward mixing valve 26.

As illustrated in FIGS. 4 and 5, optional spacers 89 are positioned between the conduits to discourage relative movement therebetween. Illustratively, spacers 89 are positioned adjacent second end 66 of first conduit 60 and about the circumference of first conduit 60 to maintain the relative position of first and second conduits 60, 62. Spacers 89 are illustratively constructed using crimped pieces of copper alloy tubing commonly used in the plumbing industry. If included, spacers 89 may, however, be constructed using any suitable material(s) and may have any shape sufficient to maintain the relative position of conduits in a diffuser such as diffuser 30 and still permit adequate flow of fluid therethrough.

A first diffuser outlet configuration is depicted in diffuser 30 of FIG. 4. A series of apertures 90, designated individually as 90A through 90K, are formed in first conduit 60 at various positions around first conduit 60 and along its length. Apertures 90 A, B, and C are formed in, approximately, the first half 92 of the length of first conduit 60. Apertures 90 D through K are positioned in, approximately, the second half 94 of the length of first conduit 60. Because apertures 90A through 90K are positioned along the length of first conduit 60, portions of fluid flowing through first conduit 60 exit through apertures 90 and mix with fluid flowing outside of first conduit 60 and in second conduit 62. Illustratively, conduit 60 has an inside diameter of about 0.8 inches and has an overall length C of about 29 inches, and conduit 62 has an inside diameter of about 1.25 inches and has an overall length A of about 24.25 inches. Second end 66 is spaced apart from cap 68 by a distance of B, illustratively about 0.75 inches. However, it is understood that other sizes for conduit 62 are within the scope of this invention.

As ‘fresh’ hot fluid (a second mass of fluid) that has been recently heated by heater 28 first flows through first conduit 60, the fresh hot fluid mixes with the previously stagnant fluid that was in first conduit 60 and is in second conduit 62. Because apertures 90A-90J are provided along the length of first conduit 60, some of the fresh hot fluid flows through the first apertures 90 (for example 90A, 90B and 90C) encountered by the fluid flow without flowing all the way to second end 66 of conduit 60, thus blending the fluid and rendering the blended fluid a temperature between the temperature of the second mass of fluid and the stagnant fluid (a first mass of fluid) temperature. As more fresh hot fluid flows into first conduit 60, the blended temperature gradually approaches that of the fresh hot fluid. By blending the fluids as such, the fresh hot fluid does not reach mixing valve 26 at full temperature all at once, but rather reaches mixing valve 26 blended with previously stagnant fluid, thus providing the mixing valve a gradual increase in fluid temperature instead of the more immediate increase obtained without this blending.

First diffuser outlet configuration depicted in FIG. 4 illustrates apertures 90A through 90J formed as holes in first conduit 60 on generally opposite sides of the conduit, formed, for example, by drilling through a first point along the length of first conduit 60 and permitting the drilling device to penetrate through the opposite side of the conduit. It is understood, however, that any number of apertures 90A through 90J may be provided along the length and circumference of conduit 60. In the illustrative embodiment, aperture 90A is positioned about 13 inches from first end 64. Aperture 90B is positioned about 17 inches from first end 64. Aperture 90C is positioned about 19 inches from first end 64. Aperture 90D is positioned about 21 inches from first end 64. Aperture 90E is positioned about 1 inch from aperture 90D. Apertures 90F through 90K are each positioned from the immediately adjacent aperture approximately the same distance as apertures 90D and 90E are spaced apart. Illustratively, apertures 90A-J are holes drilled through conduit 60 so that a pair of holes, each 180 degrees around the circumference of conduit 60 from the other, is at each position along the length of first conduit 60. Illustratively, apertures 90 are holes of 0.125 inch diameter drilled in conduit 60; however, apertures 90A-J may be of different sizes and shapes and each may be different from one or more other apertures.

Although certain illustrative outlet configurations are disclosed herein, it is within the scope of this disclosure to use any suitable shape of aperture or combination of shapes. It is also within the scope of this disclosure to space a wide range of sizes and numbers of such apertures 90 apart from one another by various distances to achieve a desired mixing of fluid inside an internal conduit with the fluid outside the internal conduit, and to maintain adequate flow through the diffuser. By way of example, additional outlet configurations are depicted in FIGS. 8 through 13.

As shown in FIGS. 1 and 2, a portion of hot fluid line 48 passes adjacent heater 28 to receive heat generated by heater 28 and heat the fluid flowing through hot fluid line 48. Illustratively, hot fluid line 48 is constructed of a copper alloy; however, use of other suitable materials are within the scope of this disclosure. For example, steel, aluminum, brass, stainless steel, and other alloys or materials that have desirable characteristics such as adequate strength, durability, corrosion resistance, and high heat transfer rates, and are suitable in particular applications.

As shown in FIG. 2, illustrative heater 28 includes a heat exchange chamber 806 through which hot fluid line 48 passes with cool fluid entering through portion 810 of hot fluid line 48 and exiting through portion 807. Illustrative heat exchange chamber 806 is sized to receive burner 114 in its base region 122. Heat exchange chamber 806 is illustratively rectangular in shape and has a plurality of fins 124 extending from a first side wall 126 to a second, opposite side wall 128. As shown in FIG. 1, heater 28 includes a flue 130, the bottom 132 of which is sized to approximate the size of top 134 of draught diverter 805, the bottom 840 of which is coupled to the top 842 of heat exchange chamber 806. Excess heat and exhaust from the combustion process passes from heat exchange chamber 806 through flue 130 and exits through top 136 of flue 130 to the atmosphere or other suitable destination. A suitable heater 28 is available in the form of a water heater model number 125 FX from Robert Bosch Corporation, Broadview, Ill., USA, although other heat exchangers are suitable, as are known in the art.

As shown in FIG. 1, heater 28 includes a fuel line 110 coupled to fuel tank 112. The burner 114, shown in FIG. 2, is sized to fit within the bottom 844 of heat exchanger 806 and couples to a fuel valve 814 that is configured to control the flow of fuel from fuel line 110 to burner 114. Illustratively, fuel valve 814 is responsive to a controller system 118, shown and described in more detail below with reference to FIGS. 16 and 17, or may have a manual control such as on/off switch 833, by which fuel valve 814 opens upon certain conditions to provide fuel. If on/off switch 833 is used, the switch may be accessed through opening 803 in cover 801, which fits around heat exchange chamber 806, burner 114, and fuel valve 814. Fuel is supplied via ports 835 and 836 and, illustratively, controller system 118 and fuel valve 814 cooperate to open fuel valve 814 and ignite fuel at burner 114 when actuator 41 is actuated by a user. It is within the scope of this disclosure for a variety of types of equipment to be used instead of or in addition to controller system 118 to determine whether, for example, power or fuel to heater 28 should be increased, or whether heater 28 should be started or ignited. For example, a typical flow sensor could be incorporated to detect flow of fluid in hot fluid line 48, and when flow is detected in line 48, heater 28 is ignited. Further, a thermocouple to detect the temperature of fluid flowing through hot fluid line 48 could likewise be incorporated. If fluid was flowing through hot fluid line 48 and the thermocouple detected a temperature below a set point, heater 28 could be started or otherwise turned up. It is understood that heater 28 is illustrative, and other heater configurations are within the scope of this disclosure.

As illustrated in the diagram of FIG. 16, cold fluid entering the heater passes through a valve assembly that allows gas to enter the burners only when fluid is flowing. A fluid flow sensor 728 signals computer 729 to light burner 732, and the gas is ignited in the illustrative gas-fueled example by the pilot or spark ignition. Illustratively, burners 732 activate at a flow rate of 0.75 gallons per minute (GPM), with about 0.6 gpm continuous flow required to maintain burners 732 lit. Fluid is heated as it flows through heat exchanger 730, which illustratively includes finned tube copper coils located adjacent burners 732. As the fluid flow rate changes, a governor (not shown) modulates the flow of gas to burners 732 to maintain a constant temperature. The size of the flames and the energy used is thus proportional to the volume of hot fluid being moved through the system. The fluid temperature can be adjusted, illustratively from about 100° to about 140° F., by adjusting gas proportioning valve 734.

Referring to FIGS. 14 and 15, a flame sensor 620 of heater 28 (shown in FIGS. 1 and 2) optionally may be positioned on pilot assembly 621 to sense when a flame 622 is present (FIG. 15), and to shut off the supply of gas upon failure of flame 622 (FIG. 14). As shown in FIG. 17, optionally a flue gas sensor 713, a high temperature limiter 707, and an overheat sensor 706 illustratively positioned in the flue, are coupled in series to an electronic control box 708, that controls a valve (not shown), the valve closing upon a signal from any one or more of these sensors to stop the flow of gas. Flow sensor 728, shown in FIG. 16 senses when the flow of fluid is stopped, similarly signaling to close a valve and shut off the flow of gas to the burners. Illustratively, heater 28 includes a push button piezo-electric pilot 624 shown in FIGS. 14 and 15, and as 705 in FIG. 17, safety interlocked controls, and an illustrative copper heat exchanger 730 illustrated in FIG. 16. Further, illustratively heater 28 includes a slow ignition valve, high-efficiency low-maintenance stainless steel burners 732, and filters (not shown) for the pilot and burners to provide clogging protection.

An alternative embodiment of a diffuser 230 is illustrated in FIG. 5. Diffuser 230 is illustrated as a three-pass diffuser and includes first conduit 232, a second conduit 234, and a third conduit 236. As shown in FIG. 5, first conduit 232 is positioned substantially within second conduit 234, and second conduit 234 is positioned substantially within third conduit 236. A first union 238 cooperates with first, second, and third conduits 232, 234, 236 to maintain the conduits in position. First union 238 includes a first section 240 and a second section 242. First section 240 includes a smaller diameter opening 244 sized to receive first conduit 232 therein. First section 240 includes a larger diameter opening 246 sized to receive the second conduit 234 therein. First section 240 includes a reducing or neck down region 248 between openings 244 and 246. Illustratively, reducing region 248 is frustoconical in shape. Second section 242 includes a smaller diameter opening 250 sized to receive the second conduit 234. Second section 242 includes a larger diameter opening 252 sized to receive the outside diameter of third conduit 236. Second section 242 includes a reducing or neck down region 254 between openings 250 and 252. Illustratively, reducing region 254 is frustoconical in shape. First section 240 and second section 242 of first union 238 may be provided as two separate pieces or may optionally be formed as a single first union part.

Diffuser 230 further includes a second union 256 spaced apart from first union 238. Second union 256 includes a larger diameter opening 258 sized to receive an outlet end 260 of third conduit 236. Second union 256 includes a smaller diameter opening 262 sized for coupling to a hot fluid line 264. Second union 256 includes a reducing or neck down region 266 between openings 258, 262. Illustratively, reducing region 266 is frustoconical in shape. End cap 226 has a side 227 sized to receive a second end 239 of second conduit 324.

While the reducing regions described above are shown and described as being frustoconical in shape, it is within the scope of this disclosure for one or more of the reducing regions to be other shapes. Further, although unions are described as being separate components from the conduits, it is within the scope of this disclosure to form diffusers from any number of pieces or to mold diffusers from a single piece. One of ordinary skill in the art will recognize that a wide variety of formation and/or assembly techniques may be implemented to make a diffuser.

First conduit 232 has a length F, illustratively about 53-54 inches. Second conduit 234 has a length E, illustratively about 50-51 inches. Third conduit 236 has a length D, illustratively about 48 inches. Illustratively, first, second, and third conduits 232, 234, 236 have inside diameters of about 1, 1.5, and 2.5, inches respectively. Diffuser 230 outlet configuration depicted in FIG. 5 illustrates apertures 290A through 290Q formed as holes in first conduit 232 and second conduit 234, each hole illustratively having a second corresponding hole on generally opposite sides of the conduit, formed, for example, by drilling through a first point along the length of the conduit and permitting the drilling device to penetrate through the opposite side of the conduit. While two opposite holes are described for each of apertures 290A through 290Q, such is illustrative, and any number of holes of any shape are within the scope of this invention.

The sizes and spacing of the apertures 290 are described for illustrative purposes herein. As shown, illustrative apertures 290A are 7/64 inch holes positioned in first conduit 232 about 12 inches from first end 233 of first conduit 232. apertures 290B are 3/32 inch holes positioned about 24 inches from first end 233, apertures 290C are 5/64 inch holes positioned about 36 inches from first end 233, apertures 290D are 1/16 inch holes positioned about 48 inches from first end 233, and apertures 290E are 1/16 inch holes positioned about 2 inches from second end 235.

Still referring to FIG. 5, illustrative apertures 290F are 9/16 inch holes positioned about 3.5 inches from first end 237 of second conduit 234 or adjacent the reducing region 254 of the second section 242 of first union 238. Illustrative apertures 290G are 9/16 inch holes positioned about 4.0 inches from first end 237 of second conduit 234, and are rotated 90 degrees around the circumference of second conduit 234 relative to apertures 290F. Illustrative apertures 290H are 9/16 inch holes positioned about 4.5 inches from first end 237 of second conduit 234, and are rotated 90 degrees around the circumference of second conduit 234 relative to apertures 290G. Illustrative apertures 290I are 9/16 inch holes positioned about 5.0 inches from first end 237 of second conduit 234, and are rotated 90 degrees around the circumference of second conduit 234 relative to apertures 290H. Illustrative apertures 290J are 9/16 inch holes positioned about 5.5 inches from first end 237 of second conduit 234, and are rotated 90 degrees around the circumference of second conduit 234 relative to apertures 290I. Illustrative apertures 290K are 9/16 inch holes positioned about 6.0 inches from first end 237 of second conduit 234, and are rotated 90 degrees around the circumference of second conduit 234 relative to apertures 290J. Illustrative apertures 290L are 9/16 inch holes positioned about 6.5 inches from first end 237 of second conduit 234, and are rotated 90 degrees around the circumference of second conduit 234 relative to apertures 290K. Illustrative apertures 290M are 9/16 inch holes positioned about 7.0 inches from first end 237 of second conduit 234, and are rotated 90 degrees around the circumference of second conduit 234 relative to apertures 290L. Illustrative apertures 290N are 3/32 inch holes positioned about 38.0 inches from second end 239 of second conduit 234. Illustrative apertures 290P are 3/32 inch holes positioned about 20.0 inches from second end 239 of second conduit 234. Illustrative apertures 290Q are 3/32 inch holes positioned about 20.0 inches from second end 239 of second conduit 234.

It is understood that fluid entering diffuser 230 at first end 233 of first conduit 232 flows upward to end cap 226, then flows downward between first conduit 232 and second conduit 234, down to aperture 290F, and then flows upward again between second conduit 234 and third conduit 236, up to and out through hot fluid line 264. As fluid flows past each of the apertures 290A through 290Q, newly heated fluid may flow through the apertures to mix with stagnant water that may already be in diffuser 230.

An alternative heater embodiment, heater 328, is depicted in FIG. 3. Heater 328 is a standard “residential” water heater, illustratively a 119 gallon water heater including a fuel line 310 coupled to fuel tank 312 and burner 314. A fuel valve (not shown) may be coupled to fuel line 310 to control flow of fuel to burner 314, and may be responsive to a controller (not shown) to provide fuel when the controller senses that additional heat is to be supplied to increase the temperature of fluid stored in heater 328. Many fuels may be used, for example natural gas, propane, or other suitable fuel types. One of ordinary skill in the art will appreciate that an electric water heater could be used for illustrative heater 328.

Heater 328 further includes a storage tank 302 in which fluid is stored that enters storage tank 302 through a fluid inlet line 340. As shown in FIG. 3, a heat exchange region 321 includes an interface 323 adjacent burner 314. Interface 323 may take a number of forms, and may include a circuit through which hot combustion gases flow such as a coil, a generally flat surface, or a heat sink extending into fluid stored in storage tank 320 to increase the surface area of interface 323 in contact with fluid in storage tank 320. If heater 328 is an electric heater, an electric element electrically coupled to an electric source could heat the fluid in storage tank 320. Optionally, a filter 347 may be provided, illustratively in fluid inlet line 340, to filter out particulate matter. Filters may be provided elsewhere in the system, illustratively in cold fluid line 346.

As shown in FIG. 3, a mixing valve 326 receives hot fluid from hot fluid line 348 and cold fluid from cold fluid line 346. As with the embodiment described with reference to FIG. 1, mixing valve 326 mixes hot and cold fluids and supplies tempered water through mixed fluid line 350. A diffuser, illustratively diffuser 230 of FIG. 5, is coupled to hot fluid inlet line 348 and is between mixing valve 326 and the fluid outlet from heater 328. An illustrative mixing valve is disclosed in U.S. Pat. No. 5,647,531 assigned to Lawler Manufacturing Company, Inc. of Indianapolis, Ind., the disclosure of which is hereby incorporated by reference herein. Other mixing valves of various configurations may be used depending on the specific requirements of the application in which the subject matter hereof is incorporated.

Still referring to FIG. 3, when a user actuates actuator 521, 526, or 532, opening a valve 522, 534, mixed fluid flows from mixed fluid outlet of the mixing valve and through mixed fluid line 350, toward fixture 510.

As shown in FIGS. 3 and 6, a combination emergency fixture 510 is illustrated. Emergency fixture 510 includes a tempered fluid inlet 512 receiving tempered water from a source such as the system shown in FIG. 3. Emergency fixture 510 includes a fluid supply line 514 coupled to fluid inlet 512, the fluid supply line being coupled to an eyewash supply line 516 and a emergency shower supply line 518. Eyewash supply line 516 is coupled to an eyewash outlet fixture 520 so that, when eyewash actuator 521 and valve 522 is actuated, fluid flows from fluid inlet 512 through fluid supply line 514, into eyewash supply line 516, and out eyewash outlet fixture 520. Basin 524 is provided to catch at least part of the refuse fluid and divert the discarded fluid into a drain line 525. An optional foot actuator 526 is coupled with a link 528 to valve 522 so that a user can actuate the eyewash by stepping on foot actuator 526. Combination emergency fixture 510 further includes an emergency shower fixture 530 coupled to the emergency shower supply line 518. A shower actuator 532 is operably coupled to a valve 534 so that when a user actuates shower actuator 532, tempered fluid flows from fluid inlet 512 through fluid supply line 514, into emergency shower supply line 518, and out emergency shower fixture outlet 536.

It is within the scope of this disclosure for heaters 28, 328 to be replaced with another suitable heating device, for example a shell and tube heat exchanger—having a heating fluid flowing therethrough (when access is had to such a heating fluid possessing sufficient heat to raise the temperature of supplied fluid by an acceptable amount).

Diffusers 30, 230 are illustratively constructed using a copper alloy. In these examples, copper is selected because of its high heat transfer rate, and resultant ability to dissipate heat contained in fluid flowing through diffusers 30, 230. However, one of ordinary skill in the art will recognize that many other materials could be used that provide desirable properties such as machinability, durability, corrosion resistance, compatibility with other system materials, cost, and the like.

In a further illustrative embodiment represented in FIG. 7, a conduit 410 is depicted. Conduit 410 may serve as the inner conduit of a diffuser, the outer conduit, or a conduit between the outer and inner conduit in a three (or more) pass diffuser. Conduit 410 includes an internal passageway 412 and an external surface 414. As shown in FIG. 7, external surface 414 includes a plurality of fins 416. Fins 416 are actually shown as a single spiral fin created using an extrusion process in which a thick-walled, illustratively copper alloy, tube is extruded to form fins 416 from surface 414. An integral finned surface 418 is thus formed on conduit 410. Fins 416 increase the surface area of external surface 414 and thus increase heat transfer into adjacent matter such as fluid flowing outside of conduit 410. It is within the scope of this disclosure to include a separate finned surface 418 constructed from a different piece of material than conduit 410 and connect separate finned surface 418 to conduit 410 to permit heat transfer during operation from conduit 410 into separate finned surface 418. It is within the scope of this disclosure to form fins 416 independently instead of as a single, spiral fin. Conduit 410 could serve as an external conduit, middle conduit (such as in a three-pass diffuser configuration) or an inner conduit. A finned conduit may be used instead of or in addition to a conduit with plurality of apertures, or, alternatively, the finned conduit may be provided with one or more apertures, to provide additional mixing.

Referring now to FIGS. 8 through 13, various aperture configurations are depicted for the apertures provided in the diffusers. These aperture configurations are provided on the internal conduits—in other words, depending on the number of passes fluid makes through a particular diffuse line, all conduits except for the outermost conduit may, or may not, include such aperture configurations. Any number of passes may be made through a diffuser, however consideration of physical, practical, and cost factors suggest that diminishing returns exist beyond a maximum number of passes. However, this maximum number of passes may vary depending on such factors as system size, pressure, and flow rate, for example. Generally, a higher number of passes should improve mixing between a first mass of fluid and a second mass of fluid adjacent the first mass upon entry into the diffuser. Further, a higher number of passes should improve heat transfer between such a first and second fluid mass, from the fluid mass(es) and to the diffuser material.

FIG. 8 shows a plurality of apertures 90 evenly spaced along the length of conduit 60. FIG. 13 similarly shows a plurality of apertures 690A through 690E. However, apertures 690A through 690 E are depicted as not evenly spaced. For example, Apertures 690D and 690E are more closely spaced than apertures 690A and 690B, and illustratively the spacing gradually decreases from 690A to 690E. A combination arrangement is shown in FIG. 4, with spacing gradually decreasing in first half 92 from aperture 90A to aperture 90D, and the spacing remaining essentially consistent between apertures in second half 94, from aperture 90D to aperture 90K. Apertures 95-98 in FIGS. 9-12 depict a variety of illustrative shapes including rhomboid, ovoid, rectangular, and parallelogram shapes. However, it is understood that these shapes are illustrative only, and that other shapes, including irregular shapes, may be included and are within the scope of this disclosure. Additionally, any shape aperture may be used with any aperture spacing to achieve the desired mixing effect of fluid in the conduit.

FIG. 8 illustrates substantially circular holes, FIG. 9 illustrates a substantially diamond (rhomboid) aperture, FIG. 10 illustrates a substantially oval aperture, FIG. 11 illustrates a substantially rectangular aperture, FIG. 12 illustrates an angularly-oriented parallelogram-shaped aperture, and FIG. 13 illustrates a series of apertures positioned at points A, B, C, D, and E along conduit 660.

Diffusers 30, 230 may also serve as heat sinks. The heat sink is a thermally conductive structure that has a mass per unit of linear length of net fluid flow greater than the average mass per unit of linear length of net fluid flow in the overall fluid flow network. Illustratively, the heat sink comprises copper. In one exemplary configuration, the heat sink surrounds a first fluid conduit such as conduits 60, 232 of FIGS. 4 and 5, so that fluid flowing from the first fluid conduit subsequently flows through a passageway defined by or otherwise through the heat sink. Further, while the diffusers illustrated herein are used in conjunction with portable emergency fixtures, it is understood that the diffusers may be used with any fixture for which temperature control is desired. Such fixtures include fixed stationary emergency fixtures, as well as sinks, showers, and any other fluid fixture. The diffusers illustrated herein may also be used in combination with hot water heaters, for whatever purpose, wherein the diffuser would be installed in the hot water line exiting from the hot water heater. Other applications for the diffusers are possible.

The following chart contains data from a test performed using a diffuser similar to the diffuser shown in FIG. 3:

Example 1

TABLE 1 Pressure Temperature Temperature Temperature of hot (° F.) (° F.) (° F.) water at of Cold of Hot of Mixed mixing Time Water Water Water point 3:00:42 PM 43.4509 171.7 84.6336 1.92 3:00:52 PM 43.3573 171.924 84.8198 3.02 3:01:02 PM 43.3417 172.67 85.6164 6.55 3:01:12 PM 43.4275 173.252 144.085 6.40 3:01:22 PM 43.4119 173.739 165.607 7.14 3:01:32 PM 43.4275 174.084 169.902 6.42 3:01:42 PM 43.4509 174.396 171.483 7.07 3:01:52 PM 43.5757 174.592 171.985 6.91 3:02:02 PM 44.0981 174.896 172.683 6.65 3:02:12 PM 45.1031 175.031 172.92 6.81 3:02:22 PM 46.2003 175.024 173.34 7.12 3:02:32 PM 47.0322 175.207 173.489 7.12 3:02:42 PM 47.7779 175.274 173.638 7.11 3:02:52 PM 48.3911 175.301 173.807 6.98 3:03:02 PM 45.5001 175.288 173.699 3.03 3:03:12 PM 44.2462 175.031 121.81 2.32 3:03:22 PM 44.1292 174.592 95.1776 1.99 3:03:32 PM 43.9032 174.497 91.0316 2.85 3:03:42 PM 43.9655 174.166 89.2846 3.01 3:03:52 PM 44.1994 173.936 88.4988 1.58 3:04:02 PM 43.7784 173.821 87.9795 2.06 3:04:13 PM 43.5133 173.631 87.8607 2.73 3:04:23 PM 43.3495 173.577 87.6083 1.67 3:04:33 PM 43.2715 173.36 83.1573 1.27 3:04:43 PM 43.1544 173.266 81.656 1.91 3:04:53 PM 43.131 173.184 81.2523 1.39 3:05:03 PM 43.0842 173.089 81.1551 2.66 3:05:13 PM 43.0452 173.029 80.9755 2.32 3:05:23 PM 42.9437 172.981 80.9306 0.05 3:05:33 PM 42.9906 172.758 81.1326 0.03 3:05:43 PM 43.014 172.649 81.3495 0.03 3:05:53 PM 43.014 172.52 82.1269 0.03 3:07:30 PM 45.8493 170.537 84.7979 0.03 3:07:32 PM 45.966 170.537 84.7979 0.03 3:07:35 PM 46.0516 170.496 84.783 0.03 3:11:16 PM 45.6476 164.755 89.4627 0.03 3:11:26 PM 45.7643 164.618 89.3071 0.03 3:11:36 PM 45.7176 164.434 89.1515 0.03 3:11:46 PM 45.7487 164.243 89.0329 0.03 3:11:56 PM 45.9277 165.308 97.7428 6.52 3:12:06 PM 47.0629 166.746 148.545 6.84 3:12:16 PM 47.3194 168.571 159.367 6.98 3:12:26 PM 47.2727 170.29 162.992 6.92 3:12:36 PM 47.3349 170.752 165.43 5.59 3:12:46 PM 46.2389 170.847 159.882 2.24 3:12:56 PM 46.0678 170.989 106.999 3.43 3:13:06 PM 46.06 171.111 99.4216 3.38 3:13:16 PM 45.8733 171.478 97.6253 2.34 3:13:26 PM 45.492 171.762 93.4761 2.47 3:13:36 PM 45.0872 172.068 92.192 2.40 3:13:46 PM 44.5108 172.244 91.8522 2.85 3:13:56 PM 44.1991 172.461 91.5567 1.63 3:14:06 PM 43.934 172.616 91.2092 2.70 3:14:16 PM 43.8405 172.691 91.1279 3.16 3:14:26 PM 43.7859 172.766 91.0466 1.84 3:14:36 PM 43.7079 172.874 88.8771 3.14 3:14:46 PM 43.7157 172.942 88.5583 2.85 3:14:56 PM 43.6767 172.921 88.3432 2.49 3:15:06 PM 43.6303 172.981 88.343 2.31 3:15:16 PM 43.5835 172.893 88.573 2.65 3:15:26 PM 43.5211 172.873 88.573 1.64 3:15:36 PM 43.4197 172.866 88.5136 3.12 3:15:46 PM 43.3417 172.839 88.0759 2.40 3:15:56 PM 43.2559 172.656 76.8887 2.40 3:16:06 PM 43.209 172.534 76.9037 1.41 3:16:16 PM 43.2012 172.5 80.2271 0.03 3:16:26 PM 43.209 172.331 80.1597 1.91 3:16:36 PM 43.2246 172.737 91.7855 7.00 3:16:46 PM 43.2246 173.238 157.181 7.02 3:16:56 PM 43.2246 173.672 168.195 6.79 3:17:06 PM 43.2402 173.956 170.493 6.81 3:17:16 PM 43.2559 174.301 171.585 6.93 3:17:26 PM 43.2793 174.423 172.222 6.69 3:17:37 PM 43.3105 174.653 172.859 6.98 3:17:47 PM 43.3963 174.72 171.266 0.03 3:17:57 PM 43.6069 174.639 170.88 0.03 3:18:07 PM 43.9804 174.581 170.149 0.03 3:18:17 PM 44.6039 173.552 170.522 1.87 3:18:27 PM 44.1987 173.187 116.597 3.45 3:18:37 PM 44.1753 173.816 105 4.21 3:18:47 PM 44.2299 173.776 107.761 6.24 3:18:57 PM 44.2299 173.952 142.44 5.79 3:19:07 PM 44.1831 174.08 158.029 5.79 3:19:17 PM 44.261 174.33 160.143 5.79 3:19:27 PM 44.339 174.303 154.455 5.66 3:19:37 PM 44.3623 174.249 150.432 5.59 3:19:47 PM 44.3857 174.445 149.94 5.84 3:19:57 PM 44.5805 174.398 148.83 0.03 3:20:07 PM 44.6221 174.299 118.859 0.03 3:20:17 PM 44.2714 174.218 71.4021 0.03 3:20:27 PM 44.1389 173.541 61.8197 0.03 3:20:37 PM 43.9804 172.353 65.3808 0.03 3:20:47 PM 43.9596 172.823 75.4319 0.45 3:20:57 PM 43.8511 173.112 81.5016 4.65 3:21:07 PM 43.8667 173.343 88.7164 5.76 3:21:17 PM 43.8511 173.674 138.142 5.57 3:21:27 PM 43.8433 173.959 146.358 5.96 3:21:37 PM 43.8667 174.182 149.282 5.31 3:21:47 PM 43.8979 174.5 150.273 5.76 3:21:57 PM 43.9758 174.561 150.717 6.08 3:22:07 PM 43.9836 174.466 151.014 5.63 3:22:17 PM 44.0304 174.594 151.346 4.22 3:22:27 PM 44.0772 174.635 139.776 3.73 3:22:37 PM 44.0694 174.703 124.316 4.40 3:22:47 PM 44.0304 174.79 124.216 4.73 3:22:57 PM 43.9914 174.703 126.607 4.47 3:23:07 PM 43.9914 174.689 126.919 4.56 3:23:17 PM 44.007 174.689 127.792 4.28 3:23:27 PM 44.0304 174.676 130.123 4.98 3:23:37 PM 44.007 174.723 131.121 4.50 3:23:47 PM 44.0304 174.696 132.166 5.07 3:23:57 PM 44.0227 174.729 134.944 5.15 3:24:07 PM 43.9838 174.675 135.331 0.03 3:24:17 PM 43.8045 174.587 107.9 0.03 3:24:27 PM 43.6485 174.181 55.0661 0.03 3:24:37 PM 43.5939 174.235 47.9435 1.58 3:24:47 PM 43.5159 172.557 55.5128 2.60 3:24:57 PM 43.4613 172.855 74.6183 1.94 3:25:07 PM 43.4223 173.207 74.5957 1.31 3:25:17 PM 43.3989 173.098 74.4224 2.68 3:25:27 PM 43.3911 172.882 78.4307 4.91 3:25:37 PM 43.4067 173.173 110.219 5.20 3:25:47 PM 43.4613 173.491 129.762 5.08 3:25:57 PM 43.4691 173.64 133.013 5.20 3:26:07 PM 43.5003 173.87 133.852 5.08 3:26:17 PM 43.5471 174.127 134.282 5.31 3:26:27 PM 43.6173 174.093 134.627 5.25 3:26:37 PM 43.5939 174.033 134.951 5.44 3:26:47 PM 43.5861 174.107 135.036 0.60 3:26:57 PM 43.5401 173.962 98.6244 0.03 3:27:07 PM 43.4387 173.82 56.8212 0.03 3:27:17 PM 43.3997 173.482 48.0761 0.03 3:27:27 PM 43.3451 173.313 45.628 0.03 3:27:38 PM 43.2593 173.164 47.3618 0.03 3:27:48 PM 43.2359 171.741 55.3284 0.03 3:27:58 PM 43.2124 171.476 59.6308 0.03 3:28:08 PM 43.1968 171.32 56.2213 0.03 3:28:18 PM 43.1344 171.144 48.1149 0.03 3:28:28 PM 43.111 170.981 44.8494 0.03 3:28:38 PM 43.0564 170.927 44.0781 0.03 3:28:48 PM 43.0252 170.757 43.8598 0.03 3:28:58 PM 42.994 170.52 44.4911 0.03 3:29:08 PM 42.955 170.18 49.4645 0.03 3:29:18 PM 42.9471 169.895 50.7347 0.03 3:29:28 PM 42.9003 169.691 51.0674 0.03 3:29:38 PM 42.9342 169.374 51.2093 0.03 3:29:48 PM 42.8938 169.229 51.1929 0.03 3:29:58 PM 42.9016 168.963 51.1233 4.77 3:30:08 PM 42.9407 170.139 90.075 4.94 3:30:18 PM 42.9407 170.703 123.685 5.31 3:30:28 PM 42.9641 171.347 129.39 5.37 3:30:38 PM 43.0187 172.012 131.364 4.60 3:30:48 PM 43.0655 172.52 130.601 4.84 3:30:58 PM 43.0967 172.947 130.601 5.21 3:31:08 PM 43.1514 172.906 130.983 5.20 3:31:18 PM 43.1358 172.798 131.315 4.88 3:31:28 PM 43.1748 173.17 131.647 4.61 3:31:38 PM 43.206 173.698 131.704 5.07 3:31:48 PM 43.2372 174.064 131.739 4.94 3:31:58 PM 43.2684 174.287 131.986 4.51 3:32:08 PM 43.3152 174.402 132.276 5.23 3:32:18 PM 43.323 174.442 132.445 5.08 3:32:28 PM 43.3698 174.524 132.636 4.23 3:32:38 PM 43.4322 174.483 132.706 5.11 3:32:48 PM 43.4406 174.515 132.663 4.55 3:32:58 PM 43.4874 174.488 132.536 4.58 3:33:08 PM 43.503 174.508 132.536 5.14 3:33:18 PM 43.5186 174.508 132.472 4.33 3:33:28 PM 43.5498 174.535 124.097 4.83 3:33:38 PM 43.5654 174.596 136.853 5.53 3:33:48 PM 43.5888 174.657 143.873 5.07 3:33:58 PM 43.6512 174.623 146.047 5.39 3:34:08 PM 43.6512 174.664 146.339 5.77 3:34:18 PM 43.6902 174.731 146.443 5.84 3:34:28 PM 43.7447 174.657 146.589 5.72 3:34:38 PM 43.7993 174.738 146.624 5.65 3:34:48 PM 43.8461 174.779 148.618 5.48 3:34:58 PM 43.9007 174.846 152.621 5.61 3:35:08 PM 43.9163 174.826 153.16 5.58 3:35:18 PM 43.9708 174.738 153.36 6.05 3:35:28 PM 44.002 174.813 153.395 5.26 3:35:38 PM 44.0569 174.818 153.463 5.28 3:35:48 PM 44.1192 174.872 153.47 5.98 3:35:58 PM 44.1816 174.859 153.504 5.84 3:36:08 PM 44.2544 174.895 153.514 4.46 3:36:18 PM 44.2934 174.875 151.779 4.84 3:36:28 PM 44.309 174.712 139.422 3.03 3:36:38 PM 44.3012 174.679 116.732 2.69 3:36:48 PM 44.2778 174.374 108.42 2.70 3:36:58 PM 44.2154 174.178 101.754 0.76 3:37:08 PM 44.1843 174.023 99.4504 1.08 3:37:18 PM 44.1609 173.671 95.4277 1.91 3:37:29 PM 44.1297 173.461 94.3308 0.03 3:37:39 PM 44.0362 173.386 88.8547 0.03 3:37:49 PM 43.927 172.953 75.2487 0.03 3:37:59 PM 43.8257 172.52 71.861 0.03 3:38:09 PM 43.7399 172.255 70.7566 0.03 3:38:19 PM 43.7009 172.086 70.1736 0.03 3:38:29 PM 43.6619 171.889 69.8857 0.03 3:38:39 PM 43.6235 171.752 66.6978 0.03 3:38:49 PM 43.5377 171.508 53.2521 0.03 3:38:59 PM 43.5221 171.379 48.2911 0.03 3:39:09 PM 43.5065 171.148 46.4735 0.03 3:39:19 PM 43.4909 171.107 45.6879 0.03 3:39:29 PM 43.4519 171.012 45.1586 0.03 3:39:39 PM 43.3739 170.741 44.9873 0.03 3:39:49 PM 43.3115 170.66 44.6913 0.03 3:39:59 PM 43.2647 170.361 44.6368 0.03 3:40:09 PM 43.2413 170.252 44.5822 0.03 3:40:19 PM 43.2023 170.089 44.5433 0.03 3:40:29 PM 43.1867 169.695 47.2817 0.03 3:40:39 PM 43.1477 169.152 49.6559 0.03 3:40:49 PM 43.1817 168.801 50.65 0.03 3:40:59 PM 43.1895 168.474 50.7661 0.03 3:41:09 PM 43.1505 168.188 51.1221 0.03 3:41:19 PM 43.1165 167.805 51.127 0.03 3:41:29 PM 43.1583 167.569 51.1453 0.03 3:41:39 PM 43.1506 166.683 51.1221 5.70 3:41:49 PM 43.1896 168.556 93.6402 5.33 3:41:59 PM 43.2442 169.31 137.937 5.51 3:42:09 PM 43.252 170.343 146.154 6.10 3:42:19 PM 43.3222 171.076 148.315 6.05 3:42:29 PM 43.3768 171.93 149.619 6.08 3:42:39 PM 43.4002 171.869 150.679 5.98 3:42:49 PM 43.4782 171.883 151.517 5.71 3:42:59 PM 43.5484 172.622 151.994 6.04 3:43:09 PM 43.6264 173.312 152.056 5.45 3:43:19 PM 43.681 173.387 151.635 0.03 3:43:29 PM 43.5328 173.238 76.0342 0.03 3:43:39 PM 43.4938 172.716 51.1144 0.03 3:43:49 PM 43.4626 172.628 46.7018 0.03 3:43:59 PM 43.2832 172.649 45.9164 0.03 3:44:09 PM 43.1896 170.696 54.4813 0.03 3:44:19 PM 43.1194 170.316 63.2646 0.03 3:44:29 PM 43.0884 170.621 62.9592 0.03 3:44:39 PM 43.0337 171.211 60.8798 0.03 3:44:49 PM 43.0259 171.116 60.5047 0.03 3:44:59 PM 42.9713 170.98 57.6287 0.03 3:45:09 PM 42.8933 170.919 56.1526 0.03 3:45:19 PM 42.8152 170.668 55.9295 0.03 3:45:29 PM 42.7528 170.315 55.7755 0.03 3:45:39 PM 42.7294 170.01 54.5354 0.03 3:45:49 PM 42.7684 170.566 54.7897 6.72 3:45:59 PM 42.7918 171.53 140.362 6.67 3:46:09 PM 42.8337 172.231 163.43 7.06 3:46:20 PM 42.8337 172.705 168.136 6.64 3:46:30 PM 42.8493 172.766 167.121 0.03 3:46:40 PM 43.1146 172.664 166.42 0.03 3:46:50 PM 43.3019 172.522 134.064 0.03 3:47:00 PM 43.2083 172.17 64.1372 0.03 3:47:10 PM 43.5281 171.919 65.7372 0.03 3:47:20 PM 43.5281 171.817 76.383 0.03 3:47:30 PM 43.5437 171.614 83.1848 0.03 3:47:40 PM 43.5671 171.485 84.8249 0.03 3:47:50 PM 43.5671 171.363 85.5247 0.03

FIG. 20 depicts a diagrammatic or schematic diagram of the test from which the above data were derived. In the test represented by the data of Table 1 and FIGS. 19A-G, and as schematically depicted in FIG. 20, a cold water line 910 from cold water supply 911 was coupled to a mixed water inlet 912, a hot water line 914 from hot water supply 913 was coupled to mixed water inlet 912. A diffuser 916 was coupled to mixed water inlet 912 so that hot and cold water flowed through mixed water inlet 912 and into diffuser 916. A mixed water outlet 918 was coupled to diffuser 916 so that water flowing from the diffuser passed through outlet 918 toward a drain (not shown). Thermocouples 920, 922, 924, were coupled to cold inlet, hot inlet, and mixed fluid outlet lines respectively to measure the temperature of the water flowing through each. A pressure sensor 926 was positioned in the hot water line to sense the pressure in the hot water. Thermocouples 920, 922, 924 and sensor 926 were coupled to computer 928 which recorded the data from each thermocouple, as depicted in Table 1 above. Valves 930 were positioned in each of the water lines to shut off or throttle flow of the hot, cold, and/or mixed water as necessary.

To simulate different stagnant hot fluid line temperatures that might be encountered in different settings, a starting mixed water temperature was arrived at by adjusting the hot 930 b and cold 930 a valves until a desired temperature was reached. For example, FIG. 19A shows a starting mixed fluid temperature of about 85 degrees F. Once the desired starting temperature for the mixed water was achieved, all flow was simultaneously shut off. Then, the hot water valve 930 b was opened full-open to simulate the hot water displacing the stagnant water in the hot water line. Mixed water temperature in the mixed water outlet line was recorded via thermocouple 924 (shown in the fourth column). Cold and hot water temperatures were recorded via thermocouples 920 and 922 in the cold and hot water lines respectively, those temperatures shown in the second and third columns respectively. The time of day each reading was made is indicated in the first column, each entry separated from the prior entry by ten seconds. The pressure, represented in the fifth column, was recorded in the hot water line, is shown in pounds per square inch gauge (psig), and serves to indicate when the hot water was opened to the full-open position.

Thermocouple 920 was about 6 feet away from the point where cold inlet line 910 connects to mixed inlet line 912, and thermocouple 922 was about 6 feet away from the point where hot inlet line 914 connects to mixed inlet line 912 (each distance of about 6 feet including about 2 feet of rubber hose). Thermocouple 924 and sensor 926 were about 5 feet away (about 3 feet of which was rubber hose) from the point where diffuser 916 connects to mixed outlet line 918.

FIGS. 19A through G represent graphically certain data from Table 1. Data were taken at ten (10) second intervals. The mixed water temperature is observed to increase to a local maximum in each of the graphs depicted in FIGS. 19A through G. The starting temperature of the mixed water was controlled by adjusting the hot valve while leaving the cold valve in the full-open position to achieve a desired starting mixed water temperature. The gradual increase in mixed water temperature, compared to plug flow through a single pass of pipe resulting in a nearly immediate jump to hot water of equal temperature with the temperature of the hot water in the water heater tank, demonstrates the effects of the diffuser.

Although this invention has been described and illustrated in detail with reference to certain illustrative embodiments, variations and modifications exist within the scope and spirit of the invention as described and defined in the following claims. 

1. An apparatus comprising: a source of first fluid; a heater receiving first fluid from the source and providing heated fluid to an outlet; a thermostatically-controlled mixing valve including a first fluid inlet, a second fluid inlet to receive a second fluid, and an outlet, said valve mixing the first fluid and the second fluid and providing mixed fluid to the outlet; an ambient outlet receiving fluid from the outlet of the valve and providing the mixed fluid to ambient conditions; a fluid mixing element having an inlet in fluid communication with the outlet of said heater, said fluid mixing element having an outlet providing fluid to the first fluid inlet of said valve, wherein fluid from the heater is received at the mixing element inlet and flows within a first flowpath in a first direction, a portion of the fluid from the first flowpath flows in a second flowpath in a second direction opposite of the first direction, and the first flowpath and the second flowpath are separated by a wall including at least one aperture for mixing the remaining portion the fluid in the first flowpath with fluid in the second flowpath.
 2. The apparatus of claim 1 wherein the wall is a first wall and the aperture is a first aperture, the fluid mixing element includes a third flowpath, the third flowpath receiving fluid from the second flowpath, the third flowpath providing fluid to said valve, and the third flowpath and the second flowpath are separated by a second wall including at least one second aperture for mixing of some of the fluid in the second flowpath with fluid in the third flowpath.
 3. The apparatus of claim 1 wherein the ambient outlet is an eyewash fixture.
 4. The apparatus of claim 1 wherein the ambient outlet is a shower fixture.
 5. The apparatus of claim 1 wherein the first fluid and the second fluid are provided from the same source.
 6. The apparatus of claim 1 wherein the heater is an electric heater.
 7. The apparatus of claim 1 wherein the heater heats the fluid from the source to about 180 degrees F.
 8. The apparatus of claim 1 further comprising a filter in the first fluid line.
 9. The apparatus of claim 1, wherein the decontamination fixture includes a valve operated by an actuator, and operation of the actuator causes fluid to flow from the heat exchanger through the mixing valve.
 10. The apparatus of claim 9, wherein said heater provides heat from combustion, and operation of the actuator causes the heater to ignite and heat the first fluid stream.
 11. The apparatus of claim 1 which further comprises a support frame supported by wheels, and said support frame supports and interconnects said heater, said mixing valve, and said mixing element.
 12. The apparatus of claim 11, further comprising a fuel tank supported by said support frame to store fuel usable by the heater to generate heat.
 13. A method for decontaminating a person, comprising: providing, a fluid heater, a mixing chamber defining a porous internal flowpath from inlet to outlet, and a thermostatically controlled mixing valve having two inlets and one outlet; heating fluid in the heater; storing fluid in the mixing chamber; providing heated fluid from the heater to the inlet of the mixing chamber; progressively mixing the stored fluid with the heated fluid through the porosity of the internal flowpath; providing fluid from the outlet of the mixing chamber to a first inlet of the valve; providing fluid cooler than the heated fluid to the second inlet of the valve; thermostatically mixing the mixed fluid and the cooler fluid within the valve; providing fluid at a controlled temperature from the outlet of the valve; and spraying the controlled temperature fluid on the person.
 14. The method of claim 13 wherein said storing is before said heating.
 15. The method of claim 13 wherein the stored fluid is cooler than the heated fluid.
 16. The method of claim 13 which further comprises delaying an increase in the temperature of fluid from the outlet of the mixing chamber by said mixing. 